CAREER: Liminal locomotion: life at the air-water-land interface

职业：阈限运动：空气-水-陆地界面的生命

• 批准号: 2144549
• 负责人: Margaret Byron
• 金额: $ 81.57万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2027-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2144549&HistoricalAwards=false
• 关键词: CAREER; Liminal; locomotion; life; air

This award is funded in whole or in part under the American Rescue Act of 2021 (Public Law 117-2). Most animals are movement specialists: swimmers, walkers, or flyers. But a few species have the unusual ability to move in all of these modes. To be this versatile, a multimodal animal must overcome the significant functional challenge of generating thrust in the divergent physical conditions of water, land, and air. Understanding how animals do this remarkable behavior remains unclear. This project studies trimodal freshwater insects — water boatmen, backswimmers, and diving beetles that swim, walk, and fly — using a biomechanical approach. To visualize the ultrafast motion of their limbs and bodies in 3D, a cutting-edge high-speed video system that can be used in the lab or outside is being developed. During swimming and underwater walking, those limb motions move the water: by tracking precisely how the water moves, the investigator will calculate thrust and gain a mechanical understanding of the behaviors. Comparing three species allows investigation of the different pathways by which the behaviors, and the body shapes that allow them, may have evolved. This research offers insights into the biology of movement versatility and the functional principles needed to invent bioinspired multimodal machines. Graduate students will be trained both in the cutting-edge techniques and in science communication and outreach, helping them integrate public service into their work from the beginning of their research careers. To put outreach into practice, graduate students will partner with two local nature centers to share insights with community members with projects designed to reach different demographics. To understand how some freshwater insects manage to achieve trimodal locomotion, high-speed videography and laser-based flow velocimetry will be combined to build a complete, three-dimensional picture of the kinematics and fluid dynamics of (1) walking in air and underwater, (2) swimming, and (3) the swimming-to-flying transition. Operating at intermediate Reynolds numbers and moving between mediums, the study species offer opportunities to study transitional fluid dynamics, for example, in the scaling of drag-based paddling, a fundamental and widespread locomotor mechanism. This is the first study to measure high-resolution flow fields generated by the swimming of the target species, the first to measure 3D velocity fields of underwater walking in any arthropod, and the first to quantify water takeoff in conjunction with flight in insects. For the takeoff from water to flight, preliminary data suggest that the behavior is driven by both surface tension and aerodynamic forces. This work will shed new light on the general biomechanical principles of free surface locomotion by developing a methodology that permits simultaneous high-resolution temporal and spatial measurement of underwater velocity fields and above-water kinematics. In addition to the important broader impact of graduate student training, this project creates a new learning community for engineering graduate students that will support public outreach efforts, not only for this project, but also for many others, spanning the breadth of the mechanical engineering discipline. These efforts will be assessed as part of an educational study on how graduate students develop into holistic scholars.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该奖项全部或部分根据2021年美国救援法案（公法117-2）资助。大多数动物都是运动专家：游泳者，步行者或飞行者。但少数物种拥有以所有这些模式移动的不寻常能力。要做到这一点，多模式动物必须克服在水、陆地和空气等不同的物理条件下产生推力的重大功能挑战。了解动物如何做到这一非凡的行为仍然不清楚。本计画以生物力学的方法研究三型淡水昆虫--水船夫、背泳者、以及会游泳、行走和飞行的潜水甲虫。为了在3D中可视化他们四肢和身体的超快运动，正在开发一种可在实验室或室外使用的尖端高速视频系统。在游泳和水下行走过程中，这些肢体运动会移动水：通过精确跟踪水的运动，研究人员将计算推力并获得对行为的机械理解。比较三个物种可以调查行为的不同途径，以及允许它们的身体形状，可能已经进化。 这项研究提供了对运动多功能性的生物学和发明生物启发多模态机器所需的功能原理的见解。研究生将接受尖端技术和科学传播和推广方面的培训，帮助他们从研究生涯开始就将公共服务融入工作。为了将外展付诸实践，研究生将与两个当地的自然中心合作，与社区成员分享见解，并通过旨在接触不同人口的项目。为了了解一些淡水昆虫如何设法实现三模态运动，高速摄像和基于激光的流速仪将结合起来，建立一个完整的三维运动学和流体动力学的图片（1）在空中和水下行走，（2）游泳，（3）游泳到飞行的过渡。在中间雷诺数和介质之间移动，研究物种提供了机会，研究过渡流体动力学，例如，在缩放的阻力为基础的划桨，一个基本的和广泛的运动机制。这是第一个测量目标物种游泳产生的高分辨率流场的研究，第一个测量任何节肢动物水下行走的3D速度场，以及第一个量化昆虫飞行中的水起飞。对于从水中起飞到飞行，初步数据表明，这种行为是由表面张力和空气动力驱动的。这项工作将揭示新的光自由表面运动的一般生物力学原理，通过开发一种方法，允许同时高分辨率的时间和空间测量水下速度场和水上运动。除了研究生培训的重要广泛影响之外，该项目还为工程研究生创建了一个新的学习社区，该社区将支持公共外展工作，不仅针对该项目，还针对跨越机械工程学科范围的许多其他项目。这些努力将作为一项教育研究的一部分进行评估，该研究旨在研究生如何发展成为全面的学者。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。